Load 2x resources on demand

ui/app_list/app_list_item_model.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/app_list/app_list_item_model.h"
 
+#include "base/logging.h"
 #include "ui/app_list/app_list_item_model_observer.h"
 
 namespace app_list {
 
 AppListItemModel::AppListItemModel() : highlighted_(false) {
 }
 
 AppListItemModel::~AppListItemModel() {
 }
 
 void AppListItemModel::SetIcon(const gfx::ImageSkia& icon) {
   icon_ = icon;
+  DCHECK(icon.IsThreadSafe());
   FOR_EACH_OBSERVER(AppListItemModelObserver, observers_, ItemIconChanged());
 }
 
 void AppListItemModel::SetTitle(const std::string& title) {
   if (title_ == title)
     return;
 
   title_ = title;
   FOR_EACH_OBSERVER(AppListItemModelObserver, observers_, ItemTitleChanged());
 }
@@ skipping 14 matching lines @@
 
 void AppListItemModel::RemoveObserver(AppListItemModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 ui::MenuModel* AppListItemModel::GetContextMenuModel() {
   return NULL;
 }
 
 }  // namespace app_list